This invention relates generally to article conveying equipment for blow molding machinery. In particular, this invention relates to article carriers for blow molding machinery of the reheat and blow type.
In reheat and blow machinery, thermoplastic article preforms each having a formed portion and a formable portion are loaded into the machine, heated to a molecular orientation temperature, and filled with an expansion fluid to biaxially stretch the formable portion to fill a mold cavity. The resulting finished article is then ejected for collection. The formed portion is left unaltered and is suitable for receiving an article closure device. It is known that to maximize throughput on such machines handling of articles must be minimized. Thus to improve overall processing throughput such machines are configured to provide continuous paths of conveyance from a preform load station to an article eject station, the empty conveyors being returned therefrom to the load station. Applicant has disclosed an article carrier suitable for use throughout such equipment in the copending application Ser. No. 257,468 assigned to the assignee of the present invention now U.S. Pat. No. 4,382,760. The carrier therein disclosed is designed for use in a single lane or conveyance path defined primarily by the construction of the reheat and blow molding sections of the machine. The result is a modular carrier and simplified conveyor drive train. Specifically, the carrier is supported by rollers riding on rails over the horizontal portions of the conveyor path and is pulled therealong by incremental advances of an engaged conveyor chain.
The carrier of the aforementioned application and, in fact, the previously known carriers which convey the articles through reheat and blow equipment by grasping the formed portion of the preforms are limited in application to the design of the formed portion for which they were originally intended. Thus, while the machine may be otherwise readily converted to production of articles having a substantially different design including a different formed portion, the article conveyors would require total replacement or complete rebuilding to accomodate substantial variations in the design of the formed portion. The present invention overcomes this disadvantage while retaining the advantages of the modular design disclosed in the aforesaid copending application.
It is therefore an object of the present invention to provide an article carrier with a rotatable, exchangeable, article gripping chuck for reheat and blow molding equipment.
It is a further object of the present invention to provide an article carrier with a rotatable, exchangeable, article gripping chuck having a passage therethrough to admit the expansion fluid to the article and a seal between the chuck and the article sufficient to contain the expansion fluid.
It is a further object of the present invention to provide an article carrier with a rotatable, exchangeable article gripping chuck having gripping means operative irrespective of the rotation of the chuck within the carrier.
Further objects and advantages of the present invention shall become apparent from the following description.